Hi,
There are also dozens of A grade farm dams but sadly access is seriously restricted. After having stayed in Cape Town for over 7 years I have never been able to access the numerous private waters that dot Grabouw, Stellenbosch, Franschoek, Paarl and Wellington.
I don't fish off a bass boat but float tube the rivers. Breede River used to be a good smallmouth bass fishery but barble made short work of them within 2 years. Now only limited pools around Swellendam hold viable smallmouth populations. Largemouth bass are however plentiful and the Bonnievale area has excellent largemoth holes. You must be patient though as the river needs to calm down from the raging torrent that it turns into at this time of the year. Anytime from late October becomes fishable.
The Olifants river around Clanwilliam has mediocre fishing. The lower Olifants river around Vredendal has cooker smallmouth fishing.
I saved the best for last, namely the Doring river. There is NO bass water in the country that compares to this river. Its remote, unpoluted and seldomly fished resulting in numerous super aggro smallmouth bass in prime condition. Access is limited but if you are serious about your bassing you will reap the rewards. Again best fished when river levels subside in late spring.
So do yourself a favour, invest in a float tube or even better a V boat and hit the rivers.
PS if any of you out there have access to primo private bass waters please invite me, I can keep a secret...